Paul Gallen says he is preparing for his first true test as a boxer when he steps into the ring against All Black Liam Messam in Auckland on Saturday.

The Australian, NSW and Cronulla forward made relatively light work of All Blacks hooker Hika Elliot in an impressive debut in Auckland this time last year.

But Gallen, 32, who has indicated a desire to fight former New Zealand heavyweight champion and dual international Sonny Bill Williams, said he was hoping to see some improvement when he fights for the second time on a Fight for Life undercard.

"I was three weeks out from groin surgery last time so I wasn't really fit then," Gallen told AAP on Tuesday.

"Saturday will be a big test of where I am at. Liam has got a bit of form, he is a tough, fit guy and I have had a limited preparation so it will be interesting to see how I go.

"He is in a similar position to me. I think the All Blacks finished up one week earlier than the Kangaroos did but that shouldn't make too much different.

"I would have liked to have gotten more sparring in and that is something I will look to do over the next couple of days.

"I honestly don't know enough about boxing to say I'm going to do this and I'm going to do that, I just want to come out of it with a win."

Gallen said he had no particular plan to continue his fighting career after the bout with Messam given the short pre-season he will have with the Sharks before the start of the new NRL season in March next year.

The Gallen/Messam match-up will take place on a bill which features hometown hero Shane Cameron's and American Brian Minto's bout for the WBO Oriental Heavyweight Title as its main drawcard.